diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 5b67cb5d47f0..edddbacf33bc 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -404,6 +404,9 @@ send_fragmentable:
 		}
 		break;
 #endif
+
+	default:
+		BUG();
 	}
 
 	up_write(&conn->params.local->defrag_sem);